Deitel - Python, How To Program.pdf

Chapter 19 Multithreading 763
Starting threads...
WAITING TO CONSUME
Produced 1 into cell 0 write 1 read 0 [1, -1, -1, -1, -1]
Consumed 1 from cell 0 write 1 read 1 [-1, -1, -1, -1, -1]
BUFFER EMPTY
Produced 2 into cell 1 write 2 read 1 [-1, 2, -1, -1, -1]
Produced 3 into cell 2 write 3 read 1 [-1, 2, 3, -1, -1]
Produced 4 into cell 3 write 4 read 1 [-1, 2, 3, 4, -1]
Consumed 2 from cell 1 write 4 read 2 [-1, -1, 3, 4, -1]
Produced 5 into cell 4 write 0 read 2 [-1, -1, 3, 4, 5]
Produced 6 into cell 0 write 1 read 2 [6, -1, 3, 4, 5]
Produced 7 into cell 1 write 2 read 2 [6, 7, 3, 4, 5]
BUFFER FULL
WAITING TO PRODUCE 8
Consumed 3 from cell 2 write 2 read 3 [6, 7, -1, 4, 5]
Produced 8 into cell 2 write 3 read 3 [6, 7, 8, 4, 5]
BUFFER FULL
Consumed 4 from cell 3 write 3 read 4 [6, 7, 8, -1, 5]
Produced 9 into cell 3 write 4 read 4 [6, 7, 8, 9, 5]
BUFFER FULL
WAITING TO PRODUCE 10
Consumed 5 from cell 4 write 4 read 0 [6, 7, 8, 9, -1]
Produced 10 into cell 4 write 0 read 0 [6, 7, 8, 9, 10]
BUFFER FULL
Producer finished producing values
Terminating Producer
Consumed 6 from cell 0 write 0 read 1 [-1, 7, 8, 9, 10]
Consumed 7 from cell 1 write 0 read 2 [-1, -1, 8, 9, 10]
Consumed 8 from cell 2 write 0 read 3 [-1, -1, -1, 9, 10]
Consumed 9 from cell 3 write 0 read 4 [-1, -1, -1, -1, 10]
Consumed 10 from cell 4 write 0 read 0 [-1, -1, -1, -1, -1]
BUFFER EMPTY
Consumer retrieved values totaling: 55
Terminating Consumer
All threads have terminated.
Fig. Fig. 19.9 19.9 Threads modifying a synchronized circular buffer (part 2 of 2).
Class SynchronizedCells (Fig. 19.10) contains six attributes—sharedCells
is a five-element list of integers that represents the circular buffer, writeable indicates
whether a producer can write into the circular buffer, readable indicates whether a consumer
can read from the circular buffer, readLocation indicates the current position
from which the next value can be read by a consumer, writeLocation indicates the
next location in which a value can be placed by a producer and threadCondition is
the condition variable that protects access to the buffer.
1 # Fig. 19.10: SynchronizedCells.py
2 # Synchronized circular buffer of integer values
Fig. Fig. 19.10 19.10 Synchronized circular buffer of integers (part 1 of 3).
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